[POLL] Do You Prefer Spontaneous or Narrated RP?

There are times when a DM/GM has masterfully created a plot that results in some deep, meaningful RP for everyone involved. There are other times when you are just playing your character among other roleplayers and cool, unexpected things happen on their own.

Which do you prefer?

This is a tough question and I'm going to have to really think about it before I vote. Please feel free to discuss!